Filter assemblies

ABSTRACT

This invention relates to a filter assembly of the kind including a head (which may be a separate part or which may be formed integrally with another part such as an engine block) having an inlet and an outlet, together with a filter unit which is attachable to the head and which is arranged in use to receive a fluid entering said inlet, the fluid then being filtered by the filter unit before flowing out of the outlet. The head is formed with an axially directed annular rim having on its inner surface an annular groove in which is located a retaining clip in the form of a length of wire. The filter unit has at one end a laterally outwardly projecting lip and the depth of the groove in relation to the thickness of the wire is such as to permit the lipped end of the filter unit to be inserted into the axially direction rim of the head and past the retaining clip. Means are also provided to draw together the ends of the retaining clip after the filter unit has been thus inserted so that the clip will engage the lip of the filter unit while a portion of the clip remains within the groove to prevent detachment of the filter unit from the head.

United States Patent Holyoak 51 Aug. 8, 1972 FILTER ASSEMBLIES [72]Inventor: Kenneth Holyoak, MistraL'Swinton Rise, Ravenshead, Nottingham,En gland 221 Filed: May 3,1971 21 Appl. 190.; 139,807

Primary Examiner-Reuben Friedman Assistant Examiner-R. W. BurksAttorney-Holman & Stern including a head (which may be a separate partor I which may be formed integrally with another part such as an engineblock) having an inlet and an outlet, together with a filter unit whichis attachable to the head and which is arranged in use to receive afluid entering said inlet, the fluid then being filtered by the filterunit before flowing out of the outlet. The head is formed with anaxially directed annular rim having on its inner surface an annulargroove in which is located a retaining clip in the form of a length ofwire. The filter unit has at one end a laterally outwardly projectinglip and the depth of the groove in relation to the thickness of the wireis such as to permit the lipped end of the filter unit to be insertedinto the axially direction rim of the head and past the retaining clip.Means are also provided to draw together the ends of the retaining clipafier the filter unit has been thus inserted so that the clip willengage the lip of the filter unit while a portion of the clip remainswithin the groove to prevent detachment of the filter unit from thehead.

3 Claim, 3 Drawing Figures ABSTRACT This invention relates to a filterassembly of the kind PATENTEU 8 I973 3,682,320

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INVENT I? 7 ATTORNEYS FILTER ASSEMBLIES This invention relates to afilter assembly of the kind including a head (which may be a separatepart or which may be formed integrally with another part such as anengine block) having an inlet and an outlet, together with a filter unitwhich is attachable to the head and which is arranged in use to receivea fluid (i.e. a liquid or gas) entering said inlet, the fluid then beingfiltered by said filter unit before flowing out of said outlet. Theobject of the present invention is to provide in a filter assembly ofthe kind specified improved means for attaching the filter unit to thehead.

In accordance with the invention there is provided a filter assembly ofthe kind specified wherein the head is formed with an axially directedannular rim having on its inner surface an annular groove in which islocated a retaining clip in the form of a length of wire, the filterunit having at one end a laterally outwardly projecting lip and thedepth of said groove in relation to the thickness of said wire beingsuch as to permit said lipped end of the filter unit to be inserted intothe axially directed rim of the head and past the retaining clip, meansbeing also provided to draw together the ends of the retaining clipafter the filter unit has been thus inserted so that the clip willengage said lip of the filter unit whilst a portion of the clip remainswithin said groove to prevent detachment of the filter unit from thehead.

Conveniently, the means for drawing together the ends of the retainingclip comprise a nut and bolt, said ends of the clip being bent to form apair of radially projecting loops through which the shank of the boltextends.

One example of a filter assembly constructed in accordance with thepresent invention will now be described with reference to theaccompanying drawing wherein FIG. 1 is a part-sectional elevation of thefilter assembly,

FIG. 2 is an enlarged scrap view showing a detail of FIG. 1 and FIG. 3is a view showing means whereby the ends of the retaining clip can bedrawn together.

The filter assembly shown in the drawings includes a head convenientlyformed as a die casting together with a filter unit 11 which comprises acasing 12 and a filter element 13. The head is provided with a fluidinlet 14 and an outlet 14a so that in use a fluid to be filtered willflow through the inlet 14 and thence into the casing 12 and through thefilter element 13 before passing out through the aforesaid outlet.

As seen in FIG. 1 the head is formed with an axially directed annularrim 15 which is formed on its inner surface with an annular groove 16(see FIG. 2) and in said groove is disposed a retaining clip 17 in theform of a length of resilient wire bent to a substantially circular formbut with the ends of said length of wire being shaped to form radiallyprojecting loops 18 as seen more particularly in FIG. 3 and whichproject through a notch or slot formed in the rim 15.

As seen in FIG. 1 the upper end of the filter unit 1 1 is provided witha laterally outwardly projecting lip 19 and the depth of said groove 16in relation to the thickness or diameter of the retaining clip 17 issuch as to permit the lipped end of the filter unit to be inserted intothe rim 15 of the head, considering the aforesaid retaining clip 17 tobe in a relatively unstressed condition. Thus as will be seen from FIG.2 the lip 19 can be pushed past the retaining clip 17, the latter beingexpanded on or towards the outer surface of the groove 16 whilst the lip19 is passing the clip 17. The lip 19 then engages an annular seal 20 ofrubber or like material whilst the retaining clip 17 springs back toengage the underside of the lip 19 as seen in FIG. 2. Furthermore, asseen in the drawing the underside of said lip 19 is inclined withrespect to a plane perpendicular to the axis of the filter unit (theangle of such inclination preferably being within the range 30 so thattightening of the retaining clip 17 will have a cam or wedging action onthe lip 19 to force the filter unit tightly into engagement with theseal 20.

Attachment of the filter unit 11 to the head 10 is completed bytightening the nut and bolt assembly indicated by reference numerals 21and 22 in FIG. 3. Thus the shank of the bolt 22 extends through the twowire loops 18, the head of the bolt being disposed on the outer side ofone loop whilst the nut 21 is disposed on the outer side of the otherloop. The two ends of the retaining clip can thus be drawn together bytightening the nut and bolt so that the retaining clip engages thefilter unit 11 securely beneath the rim 19 thereof while a portion ofsaid retaining clip 17 remains in the groove 16 to prevent detachment ofthe filter unit from the head 10. The construction is such, however,that the filter unit can very readily be changed when necessary. Ifdesired, a number of slots or notches can be formed in the rim 15 atvarious positions around the circumference thereof so that the loops 18can project through any desired slot or notch for locating the nut andbolt assembly 21 and 22 at any convenient position on said circumferencefor ease of access by a tool.

A filter assembly as above-described avoids the use of an end platewhich is commonly provided in hitherto known filter assemblies at theopposite end of the filter unit to the head and also avoids an axiallyextending central bolt and associated sealing elements for connectingtogether the head, filter unit and end plate.

I claim:

1. A filter assembly having a head which is formed with an axiallydirected annular rim having on its inner surface an annular groove inwhich is located a retaining clip in the form of a length of wire, thefilter unit having at one end a laterally outwardly projecting lip andthe depth of said groove in relation to the thickness of said wire beingsuch as to permit said lipped end of the filter unit to be inserted intothe axially directed rim of the head and past the retaining clip, meansbeing also provided to draw together the ends of the retaining clipafter the filter unit has been thus inserted so that the clip willengage said lip of the filter unit while a portion of the clip remainswithin said groove to prevent detachment of the filter unit from thehead.

2. A filter assembly as claimed in claim 1 wherein the means for drawingtogether the retaining clip comprise a nut and bolt said ends of theclip being bent to form a pair of radially projecting loops throughwhich the shank of the bolt extends.

3. A filter assembly as claimed in claim 1 wherein the said outwardlyprojecting lip is inclined with respect to a plane perpendicular to theaxis of the filter unit within the range 30 60.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTEON Patent No.3,682,320 Dated August 8, 1972 Inventor(s) Kenneth Holyoak It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

[73] Assignee: Crosland Filters Limited,

Nottingham, England Signed and sealed this 6th day of March 1973.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents

1. A filter assembly having a head which is formed with an axiallydirected annular rim having on its inner surface an annular groove inwhich is located a retaining clip in the form of a length of wire, thefilter unit having at one end a laterally outwardly projecting lip andthe depth of said groove in relation to the thickness of said wire beingsuch as to permit said lipped end of the filter unit to be inserted intothe axially directed rim of the head and past the retaining clip, meansbeing also provided to draw together the ends of the retaining clipafter the filter unit has been thus inserted so that the clip willengage said lip of the filter unit while a portion of the clip remainswithin said groove to prevent detachment of the filter unit from thehead.
 2. A filter assembly as claimed in claim 1 wherein the means fordrawing together the reTaining clip comprise a nut and bolt said ends ofthe clip being bent to form a pair of radially projecting loops throughwhich the shank of the bolt extends.
 3. A filter assembly as claimed inclaim 1 wherein the said outwardly projecting lip is inclined withrespect to a plane perpendicular to the axis of the filter unit withinthe range 30*- 60*.